Protective covering for waterproofing coating on concrete



W. R. ROOF.

v PROTECTIVE COVERING FOR WATERPROOFING COATING 0N CONCRETE.

APPLICATION FILED SEPT 12, 1921.

1,407,772, I Patented B61128, 1922.

I I I l I H5. 2 L //Z INVENTOR:

ATTORNEY UNITED STATES PATENT oFnc WALTERR. noon, on onIoAeo, ILLINOIS.

PROTECTIVE COVERING FOR WATERPROOFING COATING ON CONCRETE.

T0 all who nc it may concern:

Be it known that I, WALTER -R. Roor, a citizen of the United States,residing at Chicago, county of Cook, State of Illinois,

have invented a certain new and useful Improvement in ProtectiveCoverings for Waterproofing Coating onConcrete, and declare thefollowing to be a full, clear, and

exact description of the same, such as will enable others skilled in theart to which it pertains to make and use the same, reference being hadto the accompanying drawings, which, form a part of 'this'specification.

. In the construction of concrete bridges,

retaining walls, and the like, it is customary to coat the concretesurfaces-which are in contact with ballast or fill with a waterproofmaterial to prevent the entrance of moisture. Then, in order toprevent'the ballast or fill from cutting into the waterproofing andperforating 1t, it is customaryv to cover the latter with a suitableshield or armor. The

rincipal materials used for protective coverings' or armor are bricklaid in cement mortar or servedwith hot pitch, a plain orreinforced-cement mortar, plain or reinforced concrete, and bituminousmastic. It will be seen that protective coverings made of the materialsjust mentioned become when set, substantially monolithic slabs apt tocrack in service and, because of their comparatively unyielding nature,often causing too great a concentration of pressure at single points orlines in the waterproofing coating. Furthermore, in order to secure therequisite mechanical strength, particularly in bridge work where theload imposed by the passing rolling stock may at times be very great, itis necessary to make protective coverings of the materials heretoforementioned quite thick and adding to the vertical height between thebottom of the arch and the rails. This is quite a serious matter intrack elevation work where the clearance above roads passing underneaththe bridges should be as great as possible and the elevation ofthe railsbe kept as low as possible to reduce the amount of fill between bridgesto a minimum; while at the same time the depth of the ballast across thebridge should not be reduced below a certain minimum.

My invention has for its object to produce a simple and novel protectivecovering for waterproof concrete which shall be comparatively cheap ininitial cost, which will efiectively protect the waterproofing from ISpecification of Letters Patent. Patented Feb. 28, 1922.Applicationfiled September 12, 1921.. Serial No. 500,134.

being damaged by the overlying material,

thereon, and which may be made much thinner than coverings composed ofany of the materials heretofore mentioned.

The various features of novelty whereby my invention is characterizedwill hereinafter be pointed out with particularity in the claims; but,for a full understanding of my invention and of its objects andadvantages, reference may be had to the following detailed descriptiontaken in connection with the accompanying drawing, wherein:

Fi re 1 is a cross section through a'portion of a deck plate girderbridge embodying my invention;

Fig. 2 is a view similar to Fig. 1, showing a through. plate girderbridge or span, 7 Fig. 8 is a vertical cross section through a retainingwall in which the waterproofing is protected in accordance with Imy'invention;

Fig. 4 is a cross section through a fragment of the protective covering,on a larger.

scale than employed in Figs. 1, 2 and 3; and

Fig. 5 is a section taken approximately on line 5-5 of Fig. 4.

Referring to Fig. 1 of the drawing, 1 represents a concrete bridge floorthe upper surface of which slopes upwardly at the sides as indicated at2. The floor itself, and the slopes are covered with a layer 3 of anyusual or suitable waterproofing material. In accordance with myinvention I cover the entire area coated with waterproofing material bymeans of matched wooden boards 4, that is boards joined by tongues andgrooves. The individual boards are preferably laid parallel with theoverlying track, of which one rail 5 is shown. The boards are preferablytreated with creosote or other preservative before being placed inposition, so that the life thereof will be indefinitely prolonged. Ontop of the boards is placed the usual ballast 6 in which are set therailroad ties 7 on which the rails rest. The boards are preferably tiedtogether so as to be held against accidental displacement. This mayconven-' iently be accomplished by laying cleats 8 crosswise of theboards and fastening them to the boards by means of nails 9, asindicated in Figs. 4 and 5, or otherwise.

It will be seen that the wooden protective

